Check the PoE switch first (or near the top of your troubleshooting checklist) when APs are restarting randomly

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Wondering if anyone has had an issue with APs restarting randomly. We've experienced this with our 320s over the last few weeks. Have worked with a great Aerohive Engineer, and we'd methodically looked at logs, set up client monitors to see if that would shed any light. Finally today, all APs were restarting anywhere between every 1-10 minutes. Needless to say, our environment (Elementary school with a 1-1 program) was unusable as far as network connectivity. In working with a consultant this afternoon, we thought that maybe we should check the PoE switch (Cisco SG300). We isolated one spare 320 I had, powered it via an injector, uploaded the same config as the other APs, and sat back and watched. Immediately, it was stable. Turns out that by disabling PoE on the SG300 ports I'm using and powering the APs via the Aerohive power injectors, I've got APs that have uptime of just over 5 hours so far. I'm anxious to see how things will go through the night tonight, and then during classes tomorrow when they are under load.

Just thought I'd throw this out there...wish I would have checked the switch a week ago...

~Joel
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Joel

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Posted 5 years ago

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JR

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Hi Joel, what are the statistics for the port you were plugging the AP into? I'm curious as to what on the switch was causing that issue. Thanks for the info, this is great to know.
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Joel

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Hey JR,
After having gone back to my original configuration, using the SG300 to provide PoE, the only port stats that seemed relevant was the power draw, which was 14W, with only 1 port having PoE 'turned on'. I immediately saw the same issue...the AP320 plugged in to that PoE port began restarting randomly.

~Joel
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Joel

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Hey JR, I wish I would have documented that yesterday. I'll retrace my steps and let you know. We did seem to be well under the watt usage, but I'll document that and post my findings. Thanks for the reply.

~Joel
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T_RTI

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My Cisco switches are old and not POE 802.3af capable. The one issue I had was a BR200 rebooting due to a POE sync error. The BR200 would reboot at random times and it turned out that even though the BR200 has a power supply, it was still accepting power from the switch as well. Once I turned poe power off at the switch everything settled down fine and hasn't rebooted since.
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Joel

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Thanks for commenting T_RTI. Sounds very similar to my situation. Now that I've turned PoE power off on the ports I'm using for the AP320s, everything is very stable.

~Joel
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Deven Ducommun, Beta Program Manager

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Hi Joel,

Often with reboot issues we have found that power is often the culprit. What type of SG300 was it and how many APs were on the switch? There are a few different models and each one has a different max wattage on it so I am wondering if we were hitting the max limit on that switch. Another thing that can be done is to configure the max PoE of the AP so it will not pull more power than the switch is able to provide.